Synthesis of Polycyclic Chromeno[4,3,2‐ <i>ij</i> ]Isoquinoline‐3‐Carbonitriles in the Presence of Ammonium acetate as a Dual Rule Reagent‐Catalyst

Abstract In this paper, a two‐step process is described for the chemoselective synthesis of highly fluorescent polycyclic chromeno[4,3,2‐ ij ]isoquinoline‐3‐carbonitriles using a sequential nucleophilic addition reaction involving 4‐chloro‐3‐vinyl coumarins, α , α ‐dicyanoolefins and ammonium acetate as a source of nitrogen. In this process, it is believed that ammonium acetate is converted into ammonia and acetic acid during the reaction. Ammonia is the source of nitrogen, and the acid produced can catalyze the progress of the reaction. Single‐crystal X‐ray analysis was performed to confirm the structure of one of the typical products. In addition, the photophysical characteristics of the product 3 a were investigated through absorption and emission spectroscopy. This analysis reveals that the new heterocyclic system has impressive fluorescence characteristics. Several advantages of the presented synthetic strategy can be found in its simplicity, readily available starting materials, high‐efficiency products, highly chemoselective route, metal‐free catalyst, and ability to purify products by washing them with EtOH (96 %), a technique called GAP (Group‐Assisted‐Purification) chemistry.